1. Field of the Invention
The present invention relates generally to blowout preventers forming a part of well drilling equipment and more particularly to a sealing element for a ram type blowout preventer whereby metal support elements in the seal are locked against outward movement thereby permitting support of greater weights of smaller diameter drill pipes.
2. The Prior Art
During drilling for oil and gas, instances occur when the drill string must be sealed to prevent damage to the well and the associated equipment. Various types of blowout preventer equipment have been used in the past to provide such a seal. For example, U.S. Pat. No. 3,736,982 discloses shear type and ram type blowout preventers; U.S. Pat. No. 3,667,721 discloses a spherical type blowout preventer; and U.S. Pat. No. 4,332,367 discloses a ram type blowout preventer having a variable ram seal that can be used with various sized pipes.
The present invention is intended for use with a ram type blowout preventer and enables the device to support greater weights of smaller diameter drill pipe than previously possible.